Rennie Peppermint provides effective relief indigestion, heartburn, acid indigestion, dyspepsia, hyperacidity, gastritis, nervous indigestion, flatulence, upset stomach, indigestion during pregnancy and biliousness. Rennie Peppermint tablets contain magnesium carbonate and calcium carbonate, which work together to create an antacid that neutralize stomach acid. Rennie is a fast-acting and effective remedy that has been trusted for decades for the rapid relief of heartburn and indigestion with a tasty peppermint taste.